## Swapan Kumar Ghosh Intersections of minimal prime ideals in the rings of continuous functions

Comment.Math.Univ.Carolin. 47,4 (2006) 623-632.

Abstract:A space $X$ is called $\mu$-compact by M. Mandelker if the intersection of all free maximal ideals of $C(X)$ coincides with the ring $C_K(X)$ of all functions in $C(X)$ with compact support. In this paper we introduce $\phi$-compact and $\phi '$-compact spaces and we show that a space is $\mu$-compact if and only if it is both $\phi$-compact and $\phi '$-compact. We also establish that every space $X$ admits a $\phi$-compactification and a $\phi '$-compactification. Examples and counterexamples are given.

Keywords: minimal prime ideal, $P$-space, $F$-space, $\mu$-compact space, $\phi$-compact space, $\phi '$-compact space, round subset, almost round subset, nearly round subset
AMS Subject Classification: Primary 54C40; Secondary 46E25